The invention concerns additional novel elements and circuits for use with the devices disclosed in our copending application Ser. No. 17,634, filed Mar. 9, 1970, now U.S. Pat. No. 3,749,921. That application discloses various devices for controlling the impulses generated by the discharge of a capacitor placed either in series or in parallel with a load and, in the case of a parallel connection, having no more than one electronic switch. The application also discloses novel switching tubes for uses as such switch.